Documentation/feature-removal-schedule.txt

   1 The following is a list of files and features that are going to be
   2 removed in the kernel source tree.  Every entry should contain what
   3 exactly is going away, why it is happening, and who is going to be doing
   4 the work.  When the feature is removed from the kernel, it should also
   5 be removed from this file.
   6
   7 ---------------------------
   8
   9 What:   devfs
  10 When:   July 2005
  11 Files:  fs/devfs/*, include/linux/devfs_fs*.h and assorted devfs
  12         function calls throughout the kernel tree
  13 Why:    It has been unmaintained for a number of years, has unfixable
  14         races, contains a naming policy within the kernel that is
  15         against the LSB, and can be replaced by using udev.
  16 Who:    Greg Kroah-Hartman <greg@kroah.com>
  17
  18 ---------------------------
  19
  20 What:   RAW driver (CONFIG_RAW_DRIVER)
  21 When:   December 2005
  22 Why:    declared obsolete since kernel 2.6.3
  23         O_DIRECT can be used instead
  24 Who:    Adrian Bunk <bunk@stusta.de>
  25
  26 ---------------------------
  27
  28 What:   drivers depending on OBSOLETE_OSS_DRIVER
  29 When:   January 2006
  30 Why:    OSS drivers with ALSA replacements
  31 Who:    Adrian Bunk <bunk@stusta.de>
  32
  33 ---------------------------
  34
  35 What:   RCU API moves to EXPORT_SYMBOL_GPL
  36 When:   April 2006
  37 Files:  include/linux/rcupdate.h, kernel/rcupdate.c
  38 Why:    Outside of Linux, the only implementations of anything even
  39         vaguely resembling RCU that I am aware of are in DYNIX/ptx,
  40         VM/XA, Tornado, and K42.  I do not expect anyone to port binary
  41         drivers or kernel modules from any of these, since the first two
  42         are owned by IBM and the last two are open-source research OSes.
  43         So these will move to GPL after a grace period to allow
  44         people, who might be using implementations that I am not aware
  45         of, to adjust to this upcoming change.
  46 Who:    Paul E. McKenney <paulmck@us.ibm.com>
  47
  48 ---------------------------
  49
  50 What:   raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN
  51 When:   November 2005
  52 Why:    Deprecated in favour of the new ioctl-based rawiso interface, which is
  53         more efficient.  You should really be using libraw1394 for raw1394
  54         access anyway.
  55 Who:    Jody McIntyre <scjody@steamballoon.com>
  56
  57 ---------------------------
  58
  59 What:   Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  60 When:   July 2006
  61 Why:    V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  62         series. The old API have lots of drawbacks and don't provide enough
  63         means to work with all video and audio standards. The newer API is
  64         already available on the main drivers and should be used instead.
  65         Newer drivers should use v4l_compat_translate_ioctl function to handle
  66         old calls, replacing to newer ones.
  67         Decoder iocts are using internally to allow video drivers to
  68         communicate with video decoders. This should also be improved to allow
  69         V4L2 calls being translated into compatible internal ioctls.
  70 Who:    Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  71
  72 ---------------------------
  73
  74 What:   remove EXPORT_SYMBOL(panic_timeout)
  75 When:   April 2006
  76 Files:  kernel/panic.c
  77 Why:    No modular usage in the kernel.
  78 Who:    Adrian Bunk <bunk@stusta.de>
  79
  80 ---------------------------
  81
  82 What:   remove EXPORT_SYMBOL(insert_resource)
  83 When:   April 2006
  84 Files:  kernel/resource.c
  85 Why:    No modular usage in the kernel.
  86 Who:    Adrian Bunk <bunk@stusta.de>
  87
  88 ---------------------------
  89
  90 What:   PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  91 When:   November 2005
  92 Files:  drivers/pcmcia/: pcmcia_ioctl.c
  93 Why:    With the 16-bit PCMCIA subsystem now behaving (almost) like a
  94         normal hotpluggable bus, and with it using the default kernel
  95         infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  96         control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  97         unnecessary, and makes further cleanups and integration of the
  98         PCMCIA subsystem into the Linux kernel device driver model more
  99         difficult. The features provided by cardmgr and cardctl are either
 100         handled by the kernel itself now or are available in the new
 101         pcmciautils package available at
 102         http://kernel.org/pub/linux/utils/kernel/pcmcia/
 103 Who:    Dominik Brodowski <linux@brodo.de>
 104
 105 ---------------------------
 106
 107 What:   ip_queue and ip6_queue (old ipv4-only and ipv6-only netfilter queue)
 108 When:   December 2005
 109 Why:    This interface has been obsoleted by the new layer3-independent
 110         "nfnetlink_queue".  The Kernel interface is compatible, so the old
 111         ip[6]tables "QUEUE" targets still work and will transparently handle
 112         all packets into nfnetlink queue number 0.  Userspace users will have
 113         to link against API-compatible library on top of libnfnetlink_queue
 114         instead of the current 'libipq'.
 115 Who:    Harald Welte <laforge@netfilter.org>
 116
 117 ---------------------------
 118
 119 What:   remove EXPORT_SYMBOL(kernel_thread)
 120 When:   August 2006
 121 Files:  arch/*/kernel/*_ksyms.c
 122 Why:    kernel_thread is a low-level implementation detail.  Drivers should
 123         use the <linux/kthread.h> API instead which shields them from
 124         implementation details and provides a higherlevel interface that
 125         prevents bugs and code duplication
 126 Who:    Christoph Hellwig <hch@lst.de>
 127
 128 ---------------------------
 129
 130 What:   CONFIG_FORCED_INLINING
 131 When:   June 2006
 132 Why:    Config option is there to see if gcc is good enough. (in january
 133         2006). If it is, the behavior should just be the default. If it's not,
 134         the option should just go away entirely.
 135 Who:    Arjan van de Ven
 136
 137 ---------------------------
 138
 139 What:   START_ARRAY ioctl for md
 140 When:   July 2006
 141 Files:  drivers/md/md.c
 142 Why:    Not reliable by design - can fail when most needed.
 143         Alternatives exist
 144 Who:    NeilBrown <neilb@suse.de>
 145
 146 ---------------------------
 147
 148 What:   au1x00_uart driver
 149 When:   January 2006
 150 Why:    The 8250 serial driver now has the ability to deal with the differences
 151         between the standard 8250 family of UARTs and their slightly strange
 152         brother on Alchemy SOCs.  The loss of features is not considered an
 153         issue.
 154 Who:    Ralf Baechle <ralf@linux-mips.org>
 155
 156 ---------------------------
 157
 158 What:   eepro100 network driver
 159 When:   January 2007
 160 Why:    replaced by the e100 driver
 161 Who:    Adrian Bunk <bunk@stusta.de>
 162
 163 ---------------------------
 164
 165 What:   pci_module_init(driver)
 166 When:   January 2007
 167 Why:    Is replaced by pci_register_driver(pci_driver).
 168 Who:    Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
 169
 170 ---------------------------
 171
 172 What:   Usage of invalid timevals in setitimer
 173 When:   March 2007
 174 Why:    POSIX requires to validate timevals in the setitimer call. This
 175         was never done by Linux. The invalid (e.g. negative timevals) were
 176         silently converted to more or less random timeouts and intervals.
 177         Until the removal a per boot limited number of warnings is printed
 178         and the timevals are sanitized.
 179
 180 Who:    Thomas Gleixner <tglx@linutronix.de>
 181
 182 ---------------------------
 183
 184 What:   I2C interface of the it87 driver
 185 When:   January 2007
 186 Why:    The ISA interface is faster and should be always available. The I2C
 187         probing is also known to cause trouble in at least one case (see
 188         bug #5889.)
 189 Who:    Jean Delvare <khali@linux-fr.org>
 190
 191 ---------------------------
 192
 193 What:   remove EXPORT_SYMBOL(tasklist_lock)
 194 When:   August 2006
 195 Files:  kernel/fork.c
 196 Why:    tasklist_lock protects the kernel internal task list.  Modules have
 197         no business looking at it, and all instances in drivers have been due
 198         to use of too-lowlevel APIs.  Having this symbol exported prevents
 199         moving to more scalable locking schemes for the task list.
 200 Who:    Christoph Hellwig <hch@lst.de>
 201
 202 ---------------------------
 203
 204 What:   mount/umount uevents
 205 When:   February 2007
 206 Why:    These events are not correct, and do not properly let userspace know
 207         when a file system has been mounted or unmounted.  Userspace should
 208         poll the /proc/mounts file instead to detect this properly.
 209 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 210
 211 ---------------------------
 212
 213 What:   Support for NEC DDB5074 and DDB5476 evaluation boards.
 214 When:   June 2006
 215 Why:    Board specific code doesn't build anymore since ~2.6.0 and no
 216         users have complained indicating there is no more need for these
 217         boards.  This should really be considered a last call.
 218 Who:    Ralf Baechle <ralf@linux-mips.org>
 219
 220 ---------------------------
 221
 222 What:   USB driver API moves to EXPORT_SYMBOL_GPL
 223 When:   Febuary 2008
 224 Files:  include/linux/usb.h, drivers/usb/core/driver.c
 225 Why:    The USB subsystem has changed a lot over time, and it has been
 226         possible to create userspace USB drivers using usbfs/libusb/gadgetfs
 227         that operate as fast as the USB bus allows.  Because of this, the USB
 228         subsystem will not be allowing closed source kernel drivers to
 229         register with it, after this grace period is over.  If anyone needs
 230         any help in converting their closed source drivers over to use the
 231         userspace filesystems, please contact the
 232         linux-usb-devel@lists.sourceforge.net mailing list, and the developers
 233         there will be glad to help you out.
 234 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 235
 236 ---------------------------
 237
 238 What:   find_trylock_page
 239 When:   January 2007
 240 Why:    The interface no longer has any callers left in the kernel. It
 241         is an odd interface (compared with other find_*_page functions), in
 242         that it does not take a refcount to the page, only the page lock.
 243         It should be replaced with find_get_page or find_lock_page if possible.
 244         This feature removal can be reevaluated if users of the interface
 245         cannot cleanly use something else.
 246 Who:    Nick Piggin <npiggin@suse.de>
 247
 248 ---------------------------